user lastactivity speedup ?
 

I found this comments in code in file includes/session.php :
// if this line is removed (say to be replaced by a cron job, you will need to change all of the 'online'
// status indicators as they use $userinfo['lastactivity'] to determine if a user is online which relies
// on this to be updated in real time.
$DB_site->shutdown_query("
UPDATE " . TABLE_PREFIX . "user
SET lastactivity = " . TIMENOW . "
WHERE userid = $bbuserinfo[userid]
", 'lastvisit');

But not found somebody who use cron script for lastactivity update.
Remove this query can provide more scalability and reduce one query.
If i don't need instant showing online users and it's locations,
is it safe remove this query ?
Does worked cron job example exists ?

The last activity could be croned how? By storing the batch in a table and then running a batch of updates often? I don't see that as logical. The comment probaby has more behind it then meets the eye.

In any event, that query while it is in real time and a write, is index targeted and is of no real consequence IMO.

There are queries and then there are queries. This one is pretty friendly it appears.

If session exists then lastactivity stored in session.
I think user.lastactivity need update after logout and purge session in cron.
I monitor my mysql activity and see much locked queryes.
lastactivity not indexed. Maybe simple add index?